Duplicating machine



May 18, 1937. H. THOMPSON 2,080,447

DUPLICATING MACHINE Filed June 25, 1936 g 7 vger-*m 6 nwntoz 0 0a/s 77202706 son.

Patented May 18, 1937 iPIENTA OFFICE DUPLICATING MACHINE p Louis H. Thompson, Statesboro, Ga.

Application June 23,

3 Claims.

1936, serial No. 86,769

(Granted under the act of March 3, 1883, as

amended April 30,

This invention described herein may be manufactured and used by or for the Goverment for governmental purposes, without the payment to me of any royalty thereon.

This invention relates to duplicating machines and particularly to the hand operated rolling type Aof duplicator adapted for use with the well known stencil sheet.

The primary object of the invention is the provision of a duplicator equipped with a simple, positive, and quickly operated means of attaching and holding the stencil in place.

Another object of the invention is lthe provision of a duplicator with a means of leaving the stencil clamped on one side of the platen while it can be loosened on the other side to permit quick and easy inking of the pad, without the necessity of re-aligning the stencil. A

Another object of the invention is the provision of a rolling type of duplicator provided with an Y 'overhanging operating edge adapted to be pushed against a stack of paper upon which the printing is to be done, and thus to secure a uniform margin on the printed sheets without the use of a separate margin guide.

A further object is to provide a duplicator which is of simple and rugged construction, easily and efliciently operated and one which may be cheaply manufactured.

With these and other objects in view, this invention consists in a novel combination and arrangement of parts, to be hereinafter more fully described, and specifically pointed out in the claims.

In describing the invention in detail reference is had to the accompanying drawing, forming a part of this specification and wherein like numerals of reference indicate corresponding parts throughout the several views, in which- Fig. 1 is a perspective view of the stencil holder assembled;

Fig. 2 is a top plan View of the stencil bar;

Fig. 3 is a side elevation of the stencil bar;

Fig. 4 is an end elevation of the stencil bar, and

Fig. 5 is a fragmentary sectional view taken on the lines 5--5 of Fig. 1;

Referring to the drawing in which corresponding parts are indicated by similar reference characters, the numeral (I) indicates the handle, (2) the top plate, and (3) the platen of the duplicator. The handle is preferably provided with a screw (I I) which is rigidly attached thereto and which passes through a central opening (I2) in the top plate (2) and screws into the platen (3) as shown in dotted outline in Fig. 1. At opposite ends oi' the tcp plate (2) are attached side plates (5). These side plates (5) when attached in position by screws (I5) project slightly below the lower surface of the top plate to form abutments for stencil bars (6) and also to secure a uniform maras will be described. A

Longitudinally extending rubber strips (1) are screwed, pasted, or otherwise suitably attached to the bottom of the top plate (2), equally spaced and parallel to the overlying edges of the side plates (5). These rubber strips (l) are preferably of rectangular cross-section, and form resilient abutments to cooperate with the opposite abutments formed by the side plates (5) to retain the stencil bars (6) in clamping position, as shown in Figs. 1 and 5.

The stencil bars (6) include, a central wedging member (i3), lateral lifting member (I), `and linger grips (I5). They are preferably formed of a single strip of metal having a rectangular crosssection of less thickness than the rubber strips (l) and are bent so as to form the necessary component parts. The lifting members (I4) are formed by bending the bar at right angles to the central wedging member (I3), and the finger grips (I5) are formed by rounding the extremities of the bar and bending the same outward at to the lifting members (I4) and at 45 to the line of intersection of the lifting members (I4) with the wedging members (I3), as shown in detail in Figs. 2, 3 and 4. The finger grips are rounded off to give a thumb support for pushing the bars into position.

The platen (3) is provided with a felt pad (8) of suitable thickness, which is stretched over the curved surface thereof, and fastened at the top edges by tacks, glue, or other suitable means as indicated in Figs. 1 and 5. In order to facilitate the distribution of ink through the pad and give a better surface upon which to apply the stencil, the felt pad is covered with a thin cotton or silk cloth (9).

After attaching the ink pad, which comprises felt pad (8) and the cloth (9) which covers the same, the plate (2) may be attached to the platen by means of the screw (I I) of the handle (I) to thus assemble the duplicator for the reception of the stencil. If made of metal the platen (3), may be of hollow construction, but I prefer to make the platen of Wood or rubber and make it solid, thereby eliminating the possibility of bending the platen through dropping or otherwise striking it. The wooden construction is also much cheaper to manufacture.

No fastening device of any kind is required to Lil .stencil on the duplicator.

be attached to the stencil, since the stencil is held in place on the duplicator entirely by the stencil bars; therefore any stencil of proper size may be used. The stencil may be applied by laying it face down in proper position, over the ink pad. A piece of paper is then laid over the stencil and the paper and stencil pressed against the edge of the duplicator, and the stencil is then smoothed out on the ink pad. Thepaper is then removed and the stencil clamping bars pushed into the position shown in Fig. 1, where theynare retained by the pressure and friction of the corresponding abutments and thus hold the stencil in contact with the platen. The stencil mayralso be applied by laying it down flat on a smooth surface and rolling the duplicator across it, causing it to stick to the ink pad. The stencil bars are then pushed into position as stated above.

The preferred method of operation of the device is to engage one edge of the duplicator with one edge of a stack of paper or the like and then roll the duplicator forward and back again without lifting. HEqually good results may be obtained'by rolling the duplicator across the paper inonly one direction and then lifting it; however, this method is not as fast as the first method described.

When re-inking is necessary, one stencil clampingfbar is removedand the stencil is peeled back, the stencil being retained on the duplicator by the other clamping bar. The pad is then inked with a stiff bristle brush,.and the stencil ybrought back and clamped in proper position.

By operating as described above, a uniform margin will be'obtained, since the paper is pushed up against the overhanging operating edge of a side. plate (5), each time the duplicator comes back to the starting position. The amount of margin at the upperand lower edges of the paper may be-changed by changingV the position of the The margin von the lateral kedges of the paper may be changed by sliding the duplicator along the `stackof paper in 4the `desired direction.

It is evident that slight changes might be made in the form and arrangement of the parts described Without departing from the spirit and scope of the invention, and therefore it is not desired to be limited to the foregoing except as may be required by the claims.

Having described my invention, what I claim as new and wish to secure by Letters Patent is:

1. A duplicator comprising a support, a platen detachably connected to said support and prokvided with an arcuate inking surface adapted to receive a stencil, means comprising oppositely positioned abutments including a rigid and a resilient member depending from the end por- .tions of said support, and wedging means comprising stencil bars adapted to cooperate with said first mentioned means to detachably retain the stencil on said .arcuate inking surface.

. 2. A duplicator comprising a support, a platen detachably connected to said support and provided with an arcuate inking surface adapted to receive a stencil, means comprising side plates and resilient strips, parallely spaced and depending from said support, wedging means comprising stencil bars, provided with finger grips, and adapted to cooperate with said first mentioned means to detachably retain the stencil on said arcuate inking surface.

3. A duplicatorcomprising a support, including 

